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| author |   Octavian Purdila <octavian.purdila@intel.com> | 2016-07-08 19:13:14 +0300 |
|---|---|---|
| committer |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-07-08 21:52:36 +0200 |
| commit | 612bd01fc6e04c3ce9eb59587b4a7e4ebd6aff35 (patch) | |
| tree | 00b1df2c43e46b3a7f8dd47cb954b077e19d772e /Documentation | |
| parent | ACPI: add support for configfs (diff) | |
| download | linux-dev-612bd01fc6e04c3ce9eb59587b4a7e4ebd6aff35.tar.xz linux-dev-612bd01fc6e04c3ce9eb59587b4a7e4ebd6aff35.zip | |
ACPI: add support for loading SSDTs via configfs
New tables can be loaded by creating directories under /config/table/
and writing the AML code into the aml table attribute. Various table
attributes will be readable once the table is successfully loaded.
Unloading tables is not supported at the moment, but it can be easily
implemented once ACPI loading functions provide a table handle to be
used for unloading.
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/configfs-acpi | 29 | ||||
| -rw-r--r-- | Documentation/acpi/ssdt-overlays.txt | 14 |
2 files changed, 43 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/configfs-acpi b/Documentation/ABI/testing/configfs-acpi index 17b19dc2822d..4ab4e99aa863 100644 --- a/Documentation/ABI/testing/configfs-acpi +++ b/Documentation/ABI/testing/configfs-acpi @@ -5,3 +5,32 @@ Contact: linux-acpi@vger.kernel.org Description: This represents the ACPI subsystem entry point directory. It contains sub-groups corresponding to ACPI configurable options. + +What: /config/acpi/table +Date: July 2016 +KernelVersion: 4.8 +Description: + + This group contains the configuration for user defined ACPI + tables. The attributes of a user define table are: + + aml - a binary attribute that the user can use to + fill in the ACPI aml definitions. Once the aml + data is written to this file and the file is + closed the table will be loaded and ACPI devices + will be enumerated. To check if the operation is + successful the user must check the error code + for close(). If the operation is successful, + subsequent writes to this attribute will fail. + + The rest of the attributes are read-only and are valid only + after the table has been loaded by filling the aml entry: + + signature - ASCII table signature + length - length of table in bytes, including the header + revision - ACPI Specification minor version number + oem_id - ASCII OEM identification + oem_table_id - ASCII OEM table identification + oem_revision - OEM revision number + asl_compiler_id - ASCII ASL compiler vendor ID + asl_compiler_revision - ASL compiler version diff --git a/Documentation/acpi/ssdt-overlays.txt b/Documentation/acpi/ssdt-overlays.txt index c4b57badd0b7..5ae13f161ea2 100644 --- a/Documentation/acpi/ssdt-overlays.txt +++ b/Documentation/acpi/ssdt-overlays.txt @@ -156,3 +156,17 @@ tmp=$(mktemp) /bin/echo -ne "\007\000\000\000" | cat - $filename > $tmp dd if=$tmp of="$EFIVARFS/$name-$guid" bs=$(stat -c %s $tmp) rm $tmp + +== Loading ACPI SSDTs from configfs == + +This option allows loading of user defined SSDTs from userspace via the configfs +interface. The CONFIG_ACPI_CONFIGFS option must be select and configfs must be +mounted. In the following examples, we assume that configfs has been mounted in +/config. + +New tables can be loading by creating new directories in /config/acpi/table/ and +writing the SSDT aml code in the aml attribute: + +cd /config/acpi/table +mkdir my_ssdt +cat ~/ssdt.aml > my_ssdt/aml |